Phase-contacting apparatus is extensively used in the chemical and chemical process industry, and can be built into columns. Liquid, gas and gaseous agents of different specific weight and consisting of two or more phases are contacted in the columns, thereby ensuring reaction or interaction of the components of the various phases. One of the group of such apparatus is the so-called plate-type contactor described in British Pat. No. 1,461,533, the further development and improvement of which is a tower provided with a venting system.
In venting phase-contacting apparatus, the ascending vapor or gas opens the flow-blocking members to an extent depending on the load or pressure, until the liquid phase passes downwardly through the perforations formed in the cascade plates and through the weir of the overflow plates.
These control devices are extremely diversified. Thus for instance according to the French Pat. No. 1,237,299, they are discs or catches; according to the GFR patent No. 67,964, they are blocking plates, and a similar device is described in the GDR patent No. 2,115,338; in the arrangement in the Hungarian Pat. No. 166,433, the control devices are tilting elements with limited movement.
The common shortcoming of the prior types of apparatus is that the fundamental pressure loss is determined by the weight of the flow-blocking member, i.e. by the density and geometrical dimensions of the control unit.
This fact significantly limits the applicability or field of utilization of these apparatus. Thus, while the venting plate devices in a vacuum operation mode would be expected to be in demand, they have not gained general acceptance, or are used only to a very limited extent.